Power Factor Correction
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Power Factor Correction
The Power Factor of an electrical installation is the ratio between the power that is actually used (kW) and the power that is actually supplied (kVA). It is a measure of how efficiently an installation uses electrical energy. Most electricity suppliers charge on the basis of the energy that is supplied (kVA) to a customer installation and therefore it makes good sense to pay for the electricity you use and not the energy you are supplied. A power factor close to 1.00 will ensure the power bill is as low as possible.
A properly engineered automatic power factor correction system, connected into the main electrical switchboard provides long life and low maintenance with a guaranteed reduction of electricity bill costs. Power factor correction equipment is usually suitable for installations that have loadings greater than 100 Amps/Phase and are charged on a (kVA) “Demand” basis. A power factor of 0.9 or less should be corrected because considerable savings may be available. The payback period on equipment used to correct power factor is usually less than 24 months. Note: It is a requirement of most electricity distributors that all installations maintain a minimum Power factor of 0.9
The latest technology microprocessor controlled reactive control relays, coupled with the appropriate amount of high quality capacitors can correct the power factor to 0.98 or better and ensure the lowest possible electricity costs by eliminating power factor penalties.
A Power Factor Regulator keeps track of the power factor and automatically switches capacitors in and out as the load on the installation varies.
Implementing Power Factor Correction - what you need.
To determine whether Power Factor Correction would benefit your business, Mojarra will analyse the power demand of your installation using modern instruments such as data loggers, or electricity demand data can be obtained from your electricity supplier. The maximum kVA (or kW) and Power Factor are required to enable determination of the required Capacitance (in kVAr) to correct the installation. A check on the distortion levels would be of assistance in the design.
Voltage Optimisation or Power Factor Correction?
Ideally, you will have both. VOT and PFC work completely differently and save energy and costs in their own beneficial ways. It is recommended that the Mojarra expert energy engineering assessment team evaluate your installation for both technologies.
Power Factor: An Example -
The Power Factor of an electrical installation is the ratio of the “real” power consumed and the “apparent” power supplied to the installation. Real power is expressed in kilowatts (kW) and apparent power expressed in Kilo Volt Amps (KVA). A power factor of 0.8 means that an installation is using 80% of the power being supplied to it, so improving the power factor can have benefits.
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Example
An electrical installation has a “real” (kW) demand for electrical energy of 500kW and a power factor of 0.8. Power factor is expressed as kW/KVA, so the “apparent” power required to produce this “real” power would be 500/0.8 = 625KVA. Improving the power factor will reduce this KVA and therefore reduce the supply transformer requirements or increase the available “real” power from the transformer.
The power factor can be improved by using “Power Factor Correction Equipment”, which contain capacitors and related protection and control equipment and are connected to the main switchboard. Following improvement of the power factor to, say, 0.99 the apparent power required to produce 500kW of real power is reduced to 505KVA, a saving of 120KVA (at 415 Volts 3 phase, this is a reduction in switchboard current of 166 Amps per phase).
If the installation were being charged on a “KVA” demand basis then a real saving can be achieved eg. If the KVA demand charge is $5/KVA/Mth, then a reduction in electricity charges of $600/Mth would be available.
Ref: Electroserv Brochure REV1 Page 3 of 7 Dated: September 2011 Issue 3
To find out if Power Factor Correction is right for you
>> Call us at 1300 326 669 or request a consultation